Thread and/or fabric



Patented May 26, 1936 UNITED STATES PATENT- mm) AND/0R FABRIC Joseph I. Taylor,

North American Rayon Corporation,

Elizabethton, Tenn., assixnor to New York,

N. Y., a corporation of Delaware No Drawing. Application February 26, 1935,

Serial No. 8,306

14 Claims.

A further object of my present invention is to provide a synthetic thread or fabric having a greater strength than, and equally as good adhesion to rubber as, cotton.

Other objects will in part be pointed out, and will in part be readily seen from a perusal of the following specification:

In the industry there is a great need for a fabric or thread which will readily adhere to rubber and be of greater strength than cotton fabric or thread, and also offer less resistance to self-generated frictional heat or applied heat than cotton fabric or thread. Such a thread, for example, might be used in the cords employed in the manufacture of automobile tires. A rubberized fabric finds many uses, e. g., the reinforcement of hose, in the manufacture of belt ducks, etc. Hitherto it has beenthought that cotton, only, was adapted to this use, since the ordinary thread of artificial origin will not adhere to rubber. I have discovered a method for the manufacture of such a thread, and subsequent fabric, however, that union to or adherence with rubber may be accomplished equal to or better than the ordinary union or adhesion of cotton and rubber.

Certain types of artificial filaments are what is known as thermoplastic, such as those manufactured from the organic derivatives of cellulose. In this present specification and claims, I do not intend to cover such yarns, but merely those wherein the final product is cellulose rather than a compound thereof. By this, I do not mean to indicate that it will be impossible to cause such thermoplastic yarn or fabric to adhere to rubber, but merely that I do not consider this particular phase as embraced within the scope of the present discussion.

The following description will be given with respect to the viscose or cuprammonium process, for purposes of explanation only, and I wish it understood, as pointed out in the preceding paragraph, that I wish to be limited only to processes wherein the thread is not made of so-called organic derivatives of cellulose, such as cellulose acetate and cellulose ethers.

OFFICE A viscose solution, for example, is made up in the usual manner, and that yarn is produced.

then spun or extruded so The denier of the individual strands need not be specifically limited,

although I have made between 1 and 4.5 deniers.

use of those in the range The yarn is aftertreated in any of the well-known manners, and

then given a partial twist,

possibly varying between 2 and 8 twists per inch. By physical methods the yarn is then passed by or over a surface which will tend to roughen the individual filamefits of the thread being treated. Ordinarily from 10% to 40% of'the individual filaments will be found to have treatment. ruptured or roughened, in a direction opposite the individual threads.

twist is applied to each been broken or ruptured in this Several groups of these threads, so

are then twisted together,

to that twist first applied to That is, if a right-hand individual thread prior to the roughening or rupturing treatment, a lefthand twist is given to the group of threads.

These fully twisted treated, either as a yarn a fabric after being threads may then be or thread, per se, or as woven or knitted. The

threads or fabrics are then subjected to the action of a bath creating a shrinkage of the yarn or fabric by swelling the individual filaments, so as to impart thereto the property of elasticity.

As an example, I may employ a caustic solution varying in strength between 1 and 15%. The

time of treatment in this bath may vary in accordance with the requirements of the problem at hand.

I have discovered th threads, or fabrics at this treatment of the made therefrom, previously described, causes the thread or fabric to shrink, through the swelling action as noted, and imparts to them an elasticity of from 2 to 10%.

The thread or fabric is then treated with a stearic acid emulsion, varying in strength from 1 to 6 percent. As a 2.%% solution will giv an example, I have found that e excellent results.

An emulsion of stearic acid, in water, is very desirable. A solution, pared using ethyl alcoh By using an aqueous emulsion,

of course, might be pre- 01, or some other solvent. however, the water penetrates the fibres and allows the entrance of the stearic acid.

Later, during the vulc anizing step, I have found that the use of this stearic acid seemingly acts to set up some sort of molecular rearrangement on the surface of the fabric or thread, and the rubber which penetrates it, so that a thorough adherence of the rubbe results.

r to the fabric or thread Of course, I do not desire my present invention to be limited to the use of stearic acid, since other compounds may be employed. \Use may be made of special hydrocarbon road oils, sulphonated fatty alcohols of the type of gardinols, igepons, avivol, and the like, pine tars and certain resins, as well as compounds possessing properties similar to stearic acid, such as palmitic and oleic acid.

I therefore wish to be limited only as indicated, and do not wish to be specifically limited to stearic acid, as this compound is given by way of example only.

From a reading of this description, it will be found that several elements are necessary in order that my new and useful process may operate. It is well known that cotton, for example, will readily adhere to rubber, but it has hitherto been impossible to obtain a commercial union of rubber with synthesized yarn of cellulosic nature. One desirable element of my process rests in the combination of twists set forth. If the individual threads are first twisted in one direction, they must later be twisted, as a group of threads, in the other direction. .Secondly, the pre-rupturing or -roughening ofthe individual threads, and the subsequent treatment with asolution causing shrinkage, as noted above, are desirable elements of my invention, since they give the resultant product the ideal softness, elasticity and pliability.

Rubber, or rubber compounds, in an unvulcanized state may be contacted with this material and through vulcanization, assisted by the treatment heretofore described, insure a firm adhesion of the fabric or thread to the rubber or rubber compound.

If very fine deniers of yarn are being treated, I have found that such a rupturing as that described with respect to the ordinary deniers, need not be employed. This is applicable especially to individual filaments ranging from one denier downwardly. A possible explanation lies in the presence of a larger thread surface area when a finer denier is employed. The dividing line between very small denier not requiring the roughening and consequent rupturing, and the. larger, more ordinary, deniers wherein such mechanical treatment might be desirable, is not fixed, and I therefore do not desire to be limited to the onedenier line which is indicated by way of example only. The individual requirement of the user In the claims I refer to multiple twisted threads and by this term I intend to cover only threads which are twisted in one direction, certain of the component filaments of which are twisted in an opposite direction.

Having set forth my invention as required by the patent statutes, what I desire to claim is:

1. In the production of a material or article comprising a combination of rubber or rubber compound with a cellulosic fabric or thread of artificial origin, the steps of extruding a cellulosic solution so as to form a series of threads, twisting' the threads, roughening the individual twisted threads so that certain of the filaments thereof are ruptured or broken, twisting a plurality of these threads together by applying a twist opposite to that first applied, treating the composite twisted threads so formed with a medium causing shrinkage and imparting elasticity thereto and an agent acting to cause adherence of rubber thereto, and then treating the same with rubber or a rubber compound. I

2. In a process of the type set forth, the steps of forming a series of twisted regenerated cellulose threads, and combining the series into a single larger thread by twisting them together, the combined twist being in a direction opposite to that given each of said individual threads, and then treating the composite threads thus formed with an agent causing shrinkage of by swelling and imparting elasticity to, the same and then treating the same with a substance acting to increase the adhesion of the cellulosic product for rubber.

3. In a process of the type set forth, the steps I of forming a series of twisted threads, roughening these threads so that certain filaments thereof are ruptured or broken and combining the series into a single larger thread by twisting them together, the combined twist being in a direction opposite to that given each of said individual threads, and then treating the composite threads thus formed with an agent causing shrinkage of and imparting elasticity to, the same and then treating the same with rubber or a rubber compound. 1

4. In a process of the type set forth, the steps of forming a series of twisted regenerated cellulose threads, roughening these threads so that 25 certain filaments thereof are ruptured or broken and combining the series into a single larger thread by twisting them together, the combined twist being in a direction opposite to that given each of said individual threads and then treating the composite threads thus formed with an agent causing shrinkage of and imparting elasticity to the same, and then treating the same with a substance acting to increase the adhesion of the cellulosic product for rubber.

5. In the treatment of cellulosic products of artificial origin, including thread, yarns, fabrics made therefrom, and the like, the steps of treating the product with a substance causing shrinkage by swelling, and a substance acting to increase the adhesion of the cellulosic product for rubber.

6. The process as set forth in claim 5, wherein the adhesion-increasing substance is a fatty acid.

7. A regenerated cellulose. having elasticity imparted thereto by shrinkage and containing a rubber adhesion assisting agent, such cellulose having marked increased adhesion for rubber in comparison with untreated cellulose.

8. Yarn or fabric containing regenerated cellulose having elasticity imparted thereto by shrinkage and containing a rubber adhesion assisting agent, such cellulose having marked increased adhesion for rubber in comparison with untreated cellulose.

9. Regenerated cellulose threads which have been treated with a shrinking agent and with a substance acting to increase the adhesion of the cellulose for rubber.

10. The process as in claim 5 wherein the adhesion-increasing substance is awetting-out agent.

11. The product as in claim 7 wherein the adhesion assisting agent is afatty acid. a

12. The product as in claim '7 wherein the adhesion assisting agent is a wetting-out agent.

13. A regenerated cellulose having elasticity 

